Statements Of Cash Flows (USD $)	3 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
OPERATING ACTIVITIES
Net income	$ 4,037,110	$ 2,566,825
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	230,915	190,136
Deferred income taxes	56,573	30,758
Changes in operating assets and liabilities:
Accounts receivable	(1,459,679)	51,392
Inventories	(85,423)	104,652
Prepaid expenses and other assets	(149,273)	(101,947)
Accounts payable and accrued expenses	1,853,045	776,867
Net cash provided by operating activities	4,483,268	3,618,683
INVESTING ACTIVITIES
Purchases of fixed assets	(27,710)	0
Purchases of marketable securities	(6,404,809)	(7,712,423)
Proceeds from maturities and sales of marketable securities	4,000,000	3,855,000
Net cash used in investing activities	(2,432,519)	(3,857,423)
FINANCING ACTIVITIES
Net cash provided by financing activities	0	0
Increase in cash and cash equivalents	2,050,749	(238,740)
Cash and cash equivalents at beginning of period	1,262,300	1,262,300
Cash and cash equivalents at end of period	3,313,049	2,270,943
Supplemental disclosures of cash flow information:
Cash paid during the period for income taxes	$ 0	$ 0